Ranger J,
I shoot the Lyman 358429 Keith-style bullet in my 1894C. If I seat the bullet to the depth that allows me to crimp into the crimping groove as the bullet was designed, it will not cycle from the magazine to the chamber. The O.C.L. is simply too long because of the nose profile of the Keith-style bullet which is a SWC. However, if they are seated and crimped into the crimping groove as they were intended to be, they will work in my revolvers, whether I have loaded them in 357 Magnum or 38 Special cases. As you have found, you can singly load them into the chamber and they will shoot, but they will not cycle. Also, if you singly load them into the chamber and do not shoot them, they may not be moved back far enough when the bolt is open to allow them to be ejected—another jam situation!!!
So, since I wanted to crimp the 358429 slug in the crimping groove and still shoot it in the Marlin, I trimmed the cases back enough to allow for crimping in the crimping groove but lessen the O.C.L. My situation required approximately 0.040” to be trimmed from the 357 Magnum case. This caused the O.C.L. of these rounds to be approximately 1.604”. These will cycle in my rifle, but a few thousands less would be better. Doing this requires that these cases always be segregated from regular 357 Magnum brass.
I set-up my RCBS neck expander and seating die to reload the 38 Special case with the 358429 slug. If you have an RCBS set of dies, they used to have a washer that was inserted between the locking ring of the die and the press. This would raise the die so that I could then reload 357 Magnum rounds with the dies still set to reload 38 Special as long as the same bullet was being used for each cartridge. I just made a washer of the correct thickness so it raised the expanding and seating dies enough to reload the shorter 357 Magnum case intended for the Marlin. It required a bit of fairly precise measuring, but now I can have my dies permanently set and reload for the 38 Special, the 357 Magnum for the Marlin, and regular 357 Magnum rounds.
Finally, if you decide to go this route, you will need to do your own calculations for your particular rifle. My O.C.L. may not be correct for your rifle since you are using a different bullet than I am. Also, be careful as the internal capacity of the case is lessened by shortening it and thusly the pressure will be higher for any given normal length 357 Magnum case.
It can be a hassle, but the 358429 is the only bullet I shoot in my 38 Specials and my 357 Magnums so it works well for me. Incidentally, the 358429 is the ONLY bullet I got to shoot M.O.A. at 100 yards from the Marlin (microgroove). And I have tried hundreds of combinations over the past 24+ years in this rifle. Good-luck…BCB